I think the Drikung view is the tantras give these abilities but not the authority to use them.

What, then, does give the authority to use these abilities?

I imagine being a non-regreesing Bodhisattva, or a Buddha capable of seeing the exact consequences and karma of all involved.

"My religion is not deceiving myself."Jetsun Milarepa 1052-1135 CE

"Butchers, prostitutes, those guilty of the five most heinous crimes, outcasts, the underprivileged: all are utterly the substance of existence and nothing other than total bliss."The Supreme Source - The Kunjed Gyalpo
The Fundamental Tantra of Dzogchen Semde

That makes sense but, do you still need mantras etc at that point?
Do you not just sort of have those abilities at that point?

Do Buddhas stop practicing once they reach enlightenment? Who knows?

"My religion is not deceiving myself."Jetsun Milarepa 1052-1135 CE

"Butchers, prostitutes, those guilty of the five most heinous crimes, outcasts, the underprivileged: all are utterly the substance of existence and nothing other than total bliss."The Supreme Source - The Kunjed Gyalpo
The Fundamental Tantra of Dzogchen Semde

That makes sense but, do you still need mantras etc at that point?
Do you not just sort of have those abilities at that point?

Even the Buddhas have to obey dependent origination, law of cause and effect etc...so if mantras are one of the cause for certain phenomena to arise, then the enlightened beings still will have to use that mantras to fulfill the conditions. That is why they can't just take all our karma away and give us enlightenment. however, they do know all the exact causes and conditions for all phenomena to arise. that is why they can teach us how to practice so as to fulfill all the causes and conditions to attain enlightenment.

That makes sense but, do you still need mantras etc at that point?
Do you not just sort of have those abilities at that point?

Even the Buddhas have to obey dependent origination, law of cause and effect etc...so if mantras are one of the cause for certain phenomena to arise, then the enlightened beings still will have to use that mantras to fulfill the conditions. That is why they can't just take all our karma away and give us enlightenment. however, they do know all the exact causes and conditions for all phenomena to arise. that is why they can teach us how to practice so as to fulfill all the causes and conditions to attain enlightenment.

Well, I might be wrong here, but this is not my understanding. Don't dependent origination, law of cause and effect etc fall within relative truth? As Malcolm has said rather succinctly:

Conventionally, there is a self, there is birth, there is death, and rebirth. Conventionally, there is also karma. Ultimately there is no self, no birth, no death, no rebirth, and also no karma.

Buddhas have exhausted all karma and are beyond cause and effect. The only reason I can see for them to chant mantras, as you say, would be if they were doing so as an example for sentient beings.

That makes sense but, do you still need mantras etc at that point?
Do you not just sort of have those abilities at that point?

Even the Buddhas have to obey dependent origination, law of cause and effect etc...so if mantras are one of the cause for certain phenomena to arise, then the enlightened beings still will have to use that mantras to fulfill the conditions. That is why they can't just take all our karma away and give us enlightenment. however, they do know all the exact causes and conditions for all phenomena to arise. that is why they can teach us how to practice so as to fulfill all the causes and conditions to attain enlightenment.

Well, I might be wrong here, but this is not my understanding. Don't dependent origination, law of cause and effect etc fall within relative truth? As Malcolm has said rather succinctly:

Conventionally, there is a self, there is birth, there is death, and rebirth. Conventionally, there is also karma. Ultimately there is no self, no birth, no death, no rebirth, and also no karma.

Buddhas have exhausted all karma and are beyond cause and effect. The only reason I can see for them to chant mantras, as you say, would be if they were doing so as an example for sentient beings.

I maybe wrong too but I think it is the Dharmakaya of the Buddha that is beyond birth, death and unconditioned but the forms that they manifest in order to interact with us have to obey some laws. otherwise, as I said, they can appear to beings anywhere, anyhow they wanted and there won't be such thing called the dark aeons. Also, as I said, if they don't have to obey any laws, they can simply just make everybody enlightened which didn't happened.

"Butchers, prostitutes, those guilty of the five most heinous crimes, outcasts, the underprivileged: all are utterly the substance of existence and nothing other than total bliss."The Supreme Source - The Kunjed Gyalpo
The Fundamental Tantra of Dzogchen Semde

Even the Buddhas have to obey dependent origination, law of cause and effect etc...so if mantras are one of the cause for certain phenomena to arise, then the enlightened beings still will have to use that mantras to fulfill the conditions. That is why they can't just take all our karma away and give us enlightenment. however, they do know all the exact causes and conditions for all phenomena to arise. that is why they can teach us how to practice so as to fulfill all the causes and conditions to attain enlightenment.

Well, I might be wrong here, but this is not my understanding. Don't dependent origination, law of cause and effect etc fall within relative truth? As Malcolm has said rather succinctly:

Conventionally, there is a self, there is birth, there is death, and rebirth. Conventionally, there is also karma. Ultimately there is no self, no birth, no death, no rebirth, and also no karma.

Buddhas have exhausted all karma and are beyond cause and effect. The only reason I can see for them to chant mantras, as you say, would be if they were doing so as an example for sentient beings.

I maybe wrong too but I think it is the Dharmakaya of the Buddha that is beyond birth, death and unconditioned but the forms that they manifest in order to interact with us have to obey some laws. otherwise, as I said, they can appear to beings anywhere, anyhow they wanted and there won't be such thing called the dark aeons. Also, as I said, if they don't have to obey any laws, they can simply just make everybody enlightened which didn't happened.

I don't know what Greg means, but in Sambhogakaya and Nirmanakaya forms I don't believe Buddhas are "obeying laws". They can, nevertheless, choose to act conventionally eg Guru Rinpoche appearing to study the various forms of Buddhism, after finding his less conventional ways of appearing were not winning people over. I agree though that they can't make everybody enlightened. This has to do with karma being individual.

I don't know what Greg means, but in Sambhogakaya and Nirmanakaya forms I don't believe Buddhas are "obeying laws". They can, nevertheless, choose to act conventionally eg Guru Rinpoche appearing to study the various forms of Buddhism, after finding his less conventional ways of appearing were not winning people over. I agree though that they can't make everybody enlightened. This has to do with karma being individual.

There aren't any authentic Buddhist scriptures or authoritative commentaries that address the Buddhas as omnipotent but we do read that one of his qualities is omniscient. The fact that they are not omnipotent and creates things out of nothing like creator Gods other religions claim is precisely because of the law of dependent arising that they have to "obey" also.

Ability to choose to act conventionally or unconventionally as the example you have given is not a refutation of the fact that Buddhas do have to work within the limit of some laws. Why? For example, I have many choices to act differently in life too but you will not disagree that i am within the limits of law of dependent asring and law of karma and many other physical laws. However, the possible fact that Buddhas do have to work within the limit of dependent arising does not negate their ability to manifest unconventionally or perform inconceivable miracles and ways in order to benefit sentient beings. The fact that they are omniscient, however, does reveal to them ALL possibilities available within the Dharmadhatu that he can employ.

"Butchers, prostitutes, those guilty of the five most heinous crimes, outcasts, the underprivileged: all are utterly the substance of existence and nothing other than total bliss."The Supreme Source - The Kunjed Gyalpo
The Fundamental Tantra of Dzogchen Semde

Rather the acts of killing, etc., have an entirely different meaning, related to the stopping of winds in the central channel.

I know of those interpretations, but they are certainly not the only ones,

The Kalacakra sort of resolves all these questions.

Are you saying that the Kalacakra tantra does not contain specifically wrathful (in the literal sense) practices?
Or are you saying that the tantra resolves the practical and ethical issues of when to use them?

Any point that fully enlightened beings still use seemingly relative means to achieve aims in the relative worlds is:

Guru Rinpoche use of smoke offering to pacify local spirits and protectors that obstructed the construction of Samye monastery. Practices such as Smoke offering and mantras can produce results in the relative world based on the power of dependent arising as Mipham Rinpoche explained. So, it is not a stretch of imagination that enlightened beings still use their knowledge in details of dependent arising to achieve certain outcomes in their relative world activities.